By Tom Winter and Ken Dilanian and Rich Schapiro and David K. Li with NBC News U.S. News&bullet;
last updated:
05/12/2018

Former national security adviser Michael Flynn provided "substantial assistance" in special counsel Robert Mueller's Russia investigation, according to court papers filed Tuesday.

Prosecutors described Flynn's cooperation with federal prosecutors in a sentencing memo filed by Mueller that offered few new details of the Russia probe. Noting that Flynn met with Mueller's team 19 times, the memo says a sentence that includes no prison time is "appropriate and warranted."

"The defendant provided firsthand information about the content and context of interactions between the transition team and Russian government officials," reads the heavily-redacted memo.

Flynnpleaded guilty in December 2017 to a charge of lying to the FBI about his conversations with Russian ambassador Sergey Kislyak in the weeks before Trump took office.

The crime carries a maximum sentence of five years in prison and a fine up to $250,000, but his plea agreement says he's eligible for a sentence of six months or less and can request the court not to impose a fine.

Flynn's sentencing is set for Dec. 18.

In his plea, Flynn admitted to discussing U.S. sanctions with Kislyak in a phone call in late December 2016 and said senior members of the incoming Trump administration were aware of his efforts, which undermined the policies of the outgoing Obama administration. Flynn had urged Kislyak not to overreact to sanctions imposed by the Obama White House in response to Russian meddling in the presidential election the month before.

Flynn had earlier made "material false statements and omissions" when confronted by FBI agents about the conversations, according to court papers.

The Flynn-Kislyak phone call created turmoil in the early days of the Trump administration and sparked fresh questions about its ties to Russia.

The White House denied that Flynn had discussed sanctions with Kislyak during the call, and Vice President MIke Pence later said that Flynn had assured him that sanctions never came up.

On Jan. 26, 2017, then-acting Attorney General Sally Yates told White House counsel Don McGahn that sanctions had in fact been discussed in the call and warned that Flynn was susceptible to blackmail by the Russians.

But it wasn't until 18 days later, on Feb. 13, that Flynn was forced to resign. The White House said Flynn, a decorated retired Army lieutenant general, was fired for misleading Pence and other senior officials about his discussions with Kislyak.

Flynn,who was forced out after just three weeks on the job, is so far the only member of the Trump administration to plead guilty to a charge brought by Mueller as part of his probe into Russian election interference and potential ties to the Trump campaign.

As part of the investigation, Mueller's prosecutors have been trying to piece together what happened inside the White House over that 18-day period, according to multiple people familiar with the matter.

The filing of the Flynn sentencing memo comes amid a flurry of activity in the Mueller investigation.

Trump's former personal attorney Michael Cohen pleaded guilty last Thursday to lying to Congress about plans for a Trump Tower in Moscow.

Cohen admitted that he was not being truthful when he told the Senate Intelligence Committee that the Moscow project "ended in January 2016 and was not discussed extensively with others" in the Trump Organization.

Court documents filed by Mueller's office said the talks continued into June 2016 — in the heat of the presidential race — and for a time included discussions with Trump, his children and Russian government officials.

On Friday, Mueller's office is expected to file court papers detailing why the special counsel is withdrawing a plea agreement with former Trump campaign chairman Paul Manafort. Prosecutors say Manafort breached his plea deal by lying to federal prosecutors after agreeing to cooperate in the Russia probe.

And on Dec. 12, Cohen is expected to be sentenced in federal court in New York.